That means columbia.com is not listening on port 22 or you cannot reach at port 22 of the server. It could be reachability issues or just the server is not listening to that port for anyone. Make sure sshd is running on the remote server.
You may verify if the server is listening to ssh by issueing following command:
$ netstat -na | grep 22
*.22 *.* 0 0 49152 0 LISTEN
If you see something like *.22 then it is listening on port 22.

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